Improvement in pistons for hydraulic and other cylinders



F. A. BISHOP. Pistonsfor Hydraulic and other Cylinders.

NO- 221,390. Patented Nov. 11, 1879.

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MPEFERS, PMO QLATHOGRAPHER, WASHINGTON D C.

UNITEDSTA'IES PATENT OFFICE.

FRANCIS A. BISHOP, OF'SAN FRANCISCO, CALIFORNIA.

IMPROVEMENT IN PISTONS FOR HYDRAULIC AND OTHER CYLINDERS.

7 Specification forming part of Letters Patent No. 221,380, datedNovember 11, 1879; application filed April 21, 1879.

To all whom it may concern:

Be it known that I, FRANCIS A. Brsnor, of the city and county of SanFrancisco, and State of California, havein vented an Improved Piston forHydraulic and other Cylinders;

and I do hereby declare the following to be a,

full, clear, and exact description thereof, reference being had; to theaccompanying drawlngs.

My invention has reference to that class of pistons for hydraulic andother cylinders in which leather or other equivalent flexible substanceis used as a packing; and its object is to construct the piston-head so.that the packing can be applied or renewed in a very simple manner, andat the same time provide a cheaper construction of the piston. 7

Referring to the accompanying drawings,

Figure lis a section of the piston. Figs. 2, 3,

4, 5, 6, 7, and S'ar'e details.

Let A represent a circular disk, which, in a double-acting piston, has arim, b, projecting from its edge on both sides, thus forming a cavity orrecess on each side of the disk, but in a single-acting piston the diskcan be made with a rim-or recess only on one side. In the presentinstance I have represented a doubleacting piston.

In the centerof the disk is a hole through carry it completely aroundthe two half-blocks,

so that the middle of the leather serves as a hinge for the two parts toopen out on.

The meeting ends of the leather I scarf and overlap, so that when thehalf-blocks are closed together and the ends of the leather properlyoverlapped, a cup-shaped leather band will surround. them.

Each leather bound block has a hole in its center,-which is large enoughto admit the piston-rod, and the division of the block is through thecenter of this hole. In a doubleacting piston I use two of theseleather-bound blocks, one on each side of the circular disk A.

The divided circular block d is made of such a diameter that when it isbound with the leather band its small end will fit snugly in the cavityor recess in the side of the block A, thus bringing the edge of theleather packing between the block' and the projecting rim of the disk A.By then clamping the blocks d tightly in the recesses on opposite sidesof the disk or diaphragm A, a piston-head with two projectingcup-leathers is made.

To apply this piston-head to the piston-rod H,I make a stop, f, on thepiston-rod, nearits end. This stop can be permanent or removable. Theone shown in the present instance is simply an enlargement or fixedcollar on the rod.

The disk A being on the rod, I take the leather-bound blocks d, openthem out on their hinges, and place them over the rod, one on each sideof the disk A, until they will close together, with the rod in thecentral hole. 1 then slip them into their seats in the recessed sides ofthe disk A, and, by means of a nut, 41, and washer l on the piston-rodabove the piston-head, clamp them tightly together between the fixedcollar or enlargement f and the nut, thus clamping the edges of theleathers between the edges of the blocks and the rims of the disk,leaving the opposite edges of the leathers projecting to form thepacking. The nut 13 works on a screw-thread which is cut on thepiston-rod.

I shall usually make the inner sides of the rim 1), which projects fromthe disk A, tapering, to correspond with the beveled leatherbound edgesof the blocks 01, so that the leathers will be clamped firmly betweenthem; and I shall also make the outside faces of the blocks 01 convex,and the opposing faces of the stop f and washer l concave, tocorrespond, as shown; but these are merely incidental to the peculiarconstruction of the piston.

The chief advantage of this piston-head is the ease with which thepacking can be renewed in case it becomes worn out or injured. To dothis I only have to remove one end of the cylinder R, and lift thepiston so that the nut i can be loosened, so as to allow the block (1 tobe opened out and removed from the piston-rod, after which a new leathercan be put on it, and the block replaced and tightened in the same way,as above described.

The block d can be made of any desired substance or material; but Iprefer to make them of wood, and to secure the leathers around them bymeans of nails or tacks.

The action of the piston when at work, with a fluid or gas upon it, isfor the pressure of the substance to force the sides of the packing a(which extend above the edge of the diaphragm) against the sides of thecylinder R, thus covering the slight space between the diaphragm and thecylinder, and making a perfectly tight joint thereby.

To replace the packing when worn out, or for other purposes, thecylinderhead is released and drawn up the rod clear of the piston, whilethe same is drawn out of the cylin der. The nut i is then eased untilthe collar 1 can clearthe diskd freely. Said disk, then being in halves,can be easily removed, the diaphragm then may be raised, and the lowerdisk, (1, becomes equally accessible.

Having thus described my invention, what I claim, and desire to secureby Letters Patent, 1s-

1. In combination with a diaphragm or disk, A, provided with theprojecting rim b, the divided block d, with its beveled edge, and havingthe packing-leather 0 attached thereto, substantially as and forthepurpose described.

2. The two-part block d, provided with a beveled edge and having thepacking-leather c secured around it, so as to form a hinge for theblocks to open on, in combination with the disk or diaphragm plate A,with its projecting edge b, the fixed collar f, andclamping-nut i, allcombined and arranged to operate substantially as and for the purposedescribed.

3. The improvement in pistons for hydraulic and other cylindersconsistingin the packingleather attached to a sectional block d, whichis removable from the disk A and piston-rod, and which is adapted to beclamped in a recess in the side of the disk, so as to bind thepacking-leather between the edge of the block and edge of the recess,substantially as and for the purpose above described.

In witness whereof I have hereunto set my hand and seal.

F. A. BISHOP. [L. 8.]

Witnesses:

W. F. CLARK, W. FLOYD DUCKETT.

